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AF 447 Search to resume (part2)

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AF 447 Search to resume (part2)

Old 3rd May 2011, 12:17
  #581 (permalink)  
Join Date: Jun 2009
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Partial transcript of the recorder's recovery procedure

Here is the transcript of the procedure that we can see at 1:34 in the "premiere.plonge" video (there's indication that the document that is shown is a draft as you can notice the word 'BROUILLON' in the background of the sheet) :

Île de Sein, 24 avril 2011

Procédure de récupération des enregistreurs

Cette note décrit la procédure à mettre en oeuvre pour la récupération d'au moins un enregistreur de vol de l'A330 AF447

Pendant cette opération, les seules prises de vues réalisées le seront par le BEA et la Gendarmerie.

Toute l'opération sera filmée, de la récupération sur le fond de l'océan, la remontée avec le ROV, jusqu'à l'arrivée à bord et la mise sous scellée.

A partir de la découverte d'un enregistreur sur le fond de l'océan, un OPJ sera présent dans la salle de contrôle du ROV et observera toute la phase d'identification (photographies) et de prélèvement de l'enregistreur au fond, ainsi que la remontée du ROV.

Trois scénarios sont possibles
  • L'enregistreur est séparé et déposé sur le fond
  • L'enregistreur est attaché à son rack ou à un débris de taille suffisamment petite pour être transporté
  • L'enregistreur est attaché à un débris de grosse taille.
La solution pour placer l'enregistreur dans le panier sera discutée au moment de la découverte par l'équipe d'enquête et l'équipe ROV.

Des images du panier vide seront effectuées avant la dépose de l'enregistreur à [l']intérieur.
[Lo]rs de la remontée, dans la mesure du possible, une caméra enregistrera l'état [du p]anier.

[...] le panier est sécurisé, sur le pont, l'enregistreur devra être [placé ....]
[...ent] dans le contenant en plexiglas rempli d'eau [...]
[...] contact trop long avec l'air.
[..reur] ne sera manipulé que par un OPJ et pla[cé...]
[...] rempli d'eau douce. La phase d'ident[ification?...]
[...], mesures, relevé des plaques [...]
[...] enregistreur dans le conte[nant]
[...] continue, dans [....]
[...] et supervisées [....]
[...] scellé [...]

Potorange is offline  
Old 3rd May 2011, 12:29
  #582 (permalink)  
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Very good news on the finding and recovery of the recorders. Question: Is the BEA, like the NTSB, usually quick to release preliminary details obtained from the recorders. Or, will we have to await the findings based on all available info?
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Old 3rd May 2011, 13:36
  #583 (permalink)  
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Nice picture, Gritty.

@BJ-ENG one chrash-load to the CVR will be the falling FDR in vertical chrash....
If one follows your reasoning chain, it´s interesting to observe that the FDR seems to have suffered more damage than the CVR...
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Old 3rd May 2011, 13:47
  #584 (permalink)  
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mm43, AZR:
IIRC, specifications in the brochure about ULBs stated the radiation is 80% omnidirectionnal. This would left about 40% of the power radiated upwards. It appears BEA was just unlucky during phase I having no listening device passing close enough to pick up the signal out of noise.

BTW, while they are at it, why not throw an ULB into the water and test how far it can be detected ?
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Old 3rd May 2011, 14:15
  #585 (permalink)  
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@BJ-ENG one chrash-load to the CVR will be the falling FDR in vertical chrash....
Hmmm.... I thought these units on the 330 were not together... one on each side of the pressure bulkhead?
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Old 3rd May 2011, 14:44
  #586 (permalink)  
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I'm not 330/340 endorsed, but I've been in the bowels of a few of them... Those I can recall (perhaps all 340's? - I can't be sure) have had the FDR and CVR mounted exactly as shown in Gritty's picture.

... I wonder if the press will ever stop calling them "black boxes"?
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Old 3rd May 2011, 15:01
  #587 (permalink)  
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Originally Posted by Centrosphere View Post
Nice picture, Gritty.

If one follows your reasoning chain, it´s interesting to observe that the FDR seems to have suffered more damage than the CVR...
One falls on the other from above...or one is slammed into the other from below, pushed up by the water ?

Either way, I guess they could well have impacted each other in a flat impact with high ROD, and low forward speed

[EDIT / Note: other info points to the two recorders mouted differently to that photo on 330s, in which case this is all moot as they wouldn't be hitting each other]

It'll be interesteing to hear what damage the ULBs took and if they ever likley worked, or were simply not detected.

Last edited by infrequentflyer789; 3rd May 2011 at 16:56.
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Old 3rd May 2011, 15:44
  #588 (permalink)  
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Full confession: I was a Doubting Thomas. Based on the assumption (wrong) that the aircraft went down in the "underwater mountainous terrain" area, which luckily is not where it hit the ocean, I figured that search would be fruitless once the first two phases came up empty.

Thankfully, I was very, very wrong.

What a bugger of a search problem.

The determination to find the remains of AF447 has not only been successful, but the team found the proverbial needles in the haystacks -- the recorders that will hopefully tell the tale of how it all went down.

I salute the folks who did the damnably hard work of looking at what wasn't working, trying again, and getting down there to locate, and retrieve, that which will unravel the mystery of why the flight deck crew could not recover from whatever interrupted the flight to Paris.

Here's hoping the recorders will divulge their data ...
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Old 3rd May 2011, 15:45
  #589 (permalink)  
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I understand that during the recovery process for the recorders it has been found that to best preserve them and protect the contents they should be kept submerged.
Look at the Bea released photo's it does appear that the first recovered FDR is now sealed into a liquid filled container, (is it distilled water?), but the picture showing its extraction onto the ship seems to show it inside a mesh cage or lifting box and exposed to the atmos.

If this is the case, how rapidly will corrosion occur and will it occur in such a brief span of time, (as this hopefully was).
I have seen corrosion occur in a matter of ours on some materials, but will the fairly extreme conditions the recorders have been in affect how rapidly they can corrode.

Appreciative thanks to the airbus savvy and technical folks who have posted on here and fought the long fight against the conspiracy folks.
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Old 3rd May 2011, 15:46
  #590 (permalink)  
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CVR / DFDR respectives positions

To put the matter to rest :
- CVR is located before frame 73
- DFDR is located after frame 83
on the A330.
And between them is the rear pressure bulkhead (frame 80).
Quite hard to one of them ramming in the other one.

Last edited by llagonne66; 3rd May 2011 at 15:56. Reason: Adding bulkhead frame number
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Old 3rd May 2011, 15:58
  #591 (permalink)  
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maby the picture was from an A 320
I´am not shure,
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Old 3rd May 2011, 16:05
  #592 (permalink)  
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Right on !
Both recorders on A320 are just before frame 74 as on the photo posted above.

Last edited by llagonne66; 3rd May 2011 at 16:06. Reason: Adding "A320" for clarity
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Old 3rd May 2011, 16:18
  #593 (permalink)  
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I should know my memory is not to be trusted. My apologies.
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Old 3rd May 2011, 16:26
  #594 (permalink)  
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Tail Fin separation (before or at sea surface crash?)

When AF447 lost it?
Jal 123 crashed. (LOC, but lost hydraulics too)

And it occurred also during test flights of CV880 and E8.

Instead test pilot Charles Fischer landed a B52:

RR_NDB is offline  
Old 3rd May 2011, 16:28
  #595 (permalink)  
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Possible crack ?? (FDR)

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Old 3rd May 2011, 16:44
  #596 (permalink)  
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some observations on drift analysis and ULBs

With the two recorders retrieved and at least one of the two Dukane ULB's, it may be interesting to revisit some of the material on the earlier search phases.

It is striking that the "retro drift points" of the Brazilian Navy and of the US Coast Guard as mentioned in BEA's December 2009 interim report (page 80) are both less than 10NM away from the actual impact zone. They used the same model (NCOM - Navy Coastal Ocean Model, page 79). With hindsight quite accurate, taking into account the complaints about absence of sufficient reliable data on winds and currents close to the accident date.

The 2 June 2009 BEA Interim report states (page 46) that the ULB's had a limited signal propagation range of "two kilometres at most". Based on GPS data, the METRON analysis (figure 17, page 20) establishes that the US Navy TPL, tugged by the Fairmount Glacier, went 8 times over the 10NM (~ 18,5 km) quadrant (J30) of the impact zone before 1 July 2009 (i.e. within the 30 days of the ULB's certified operating life) with a "spacing of 2,5 km" (page 48 of BEA's interim report of June 2009), to take into account the "scan swath of the TPL which is approximately 2 NM" (= 3.7 km). This in turn is in line with the METRON report, which states on page 21: "The TPL sensors were assessed to detect the ULBs at a lateral range of 1730m with a POD of 0.90" (2x1730~3,45 km). On page 47 of the BEA interim report of June 2009 it is stated that the TPLs had an "average detection range" of "at least" two kilometres per TPL trawl. Presuming that the TPL, as foreseen, was trawled close to the (flat) ocean floor, this operation would have had a higher than 0.90 probability of detection at the time. Certainly now it seems that both recorders have been lying around unobstructed on that same (flat) and relatively firm ocean floor.

That is of course if one or both ULB's had functioned as per their certification. The METRON report also states that based on a series of aviation accident that ended up in water, it is relatively rare that one or both ULB's do not function. The estimate of a 90% survival rate for the ULBs may itself be low for a crash at sea that does not involve a fire, the report states.

We all know that the TPL operation was unsuccessful. It seems therefore of importance that the ULB's are inspected for possible reasons of failure. One has been retrieved with the CVR. Finding the one belonging to the DFDR may still be a priority for BEA.

PS @ grity: the photo you posted with the DFDR and CVR mounted on top of each other does not reflect the situation on board of AF447. The METRON analysis clearly states (figure 16 on page 19) that the CVR was mounted between FR71 and FR72, while the DFDR was located between frames 83 and 84.
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Old 3rd May 2011, 17:34
  #597 (permalink)  
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some observations on drift analysis and ULBs

D Bru ,

Reason for not searching so near the LKP
I was always wondering why.

May be simple:

It seems because they tried to hear ULB as you mentioned.

After ULB´s batteries nominal endurance they abandoned "sites near LKP"


It seems like an "strategy error" (procedural error)

Because area near LKP is small compared to areas of 1, 2 and 3 phases.

Easy to say now...
RR_NDB is offline  
Old 3rd May 2011, 18:07
  #598 (permalink)  
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Yes, easy to say, but it brings up a flaw in the Search strategy. At the outset, and as early as possible, the BEA trumpeted, "Intact at Impact". Then the reliance was on ACARS to entertain "Continued Flight" into weather, and all manner of Radar excuses. This is how it must be read. A "Search" must include ALL areas that are possible, even those that fly in the face of the "Reputation" of what are arguably collateral players, pilots, union, Thales, AB, etc.

An upset and lack of recovery is not fatal to an argument that ACARS reception demanded controlled and continued flight after LKP, a situation which fed the biases of AB, AF, the Union, and frankly the heartstrings and prejudices of all who wished at least a fighting chance for our people.

Keeping 10nm away from LKP is (was) inexcusable, boneheaded, and incompetent. No human endeavour can trump Physics, let alone the parochial attitude of those involved. Why again is the DFDR inside the fuselage and not the Vertical Stabiliser ?? Given the "Good Luck" Airbus demonstrates re: the independent ability of the VS to survive horrendous crashes??

Two sayings on the wall. "Nature is relentless in her punishment of those whom are ill-prepared."

"No one deserves applause for doing what they are supposed to do."

Last edited by bearfoil; 3rd May 2011 at 18:18.
Old 3rd May 2011, 18:26
  #599 (permalink)  
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A/C direction* when hit sea surface


Before i comment your post #598


Is the picture showing the debris field an indication of the plane´s TRAJECTORY? ("heading")

Estimated as approx. 250 degrees (SW)

(*) DIRECTION is not necessarily the same of HEADING during unusual attitude

Last edited by RR_NDB; 3rd May 2011 at 21:32. Reason: comm. impvmt.
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Old 3rd May 2011, 18:38
  #600 (permalink)  
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Just an idea.
A roll of dayglo orange tape, say 50 feet long should be attached to the CVR and FDR so that it will unfurl and make them easier to find.
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